Consumer and enterprise devices such as smart phones and mobile computers hold a large amount of proprietary information including personal and business critical data. To protect such devices from unauthorized use, a password is typically required to authenticate a user with the device. Most devices typically require a three (3) or four (4) digit numeric or alphanumeric codes. While longer and more secure passwords are desirable, the difficulty of entering elaborate passwords in handheld devices leads most users to opt for simpler passwords with fewer digits.
Electronic devices may employ touch screens as a user interface for user interaction with the electronic device such as to present information to a user and also receive input from the user. User interactions, for example, may include entering security information such as passwords to access the electronic device and/or accounts within the electronic device. Users may use their fingers and/or another physical mechanism such as a stylus to interact with the touch screen, which may leave identifying marks on the surface of the touch screen. These marks can be inferred as the recently touched areas of the screen and therefore may unintentionally reveal the security information (e.g. password) to other users. In this manner, an unauthorized user may then be able to interpret the pattern of the identifying marks on the surface of the touch screen. Accordingly, there is a need for an improved mechanism to protect such devices from unauthorized use.
Skilled artisans will appreciate that elements in the figures are illustrated for simplicity and clarity and have not necessarily been drawn to scale. For example, the dimensions of some of the elements in the figures may be exaggerated relative to other elements to help to improve understanding of embodiments of the present invention.
The apparatus and method components have been represented where appropriate by conventional symbols in the drawings, showing only those specific details that are pertinent to understanding the embodiments of the present invention so as not to obscure the disclosure with details that will be readily apparent to those of ordinary skill in the art having the benefit of the description herein.